Abstract
A recently arrived plant-killing scale insect, Aulacaspis yasumatsui Takagi, the cycad aulacaspsis scale (CAS), has eliminated many queen and king sagos (cycads) from south Florida landscapes in recent years. Results, with one application of foliar applied insecticides, were evaluated. Applications were made on October 1, 2002 to evaluate potential efficacy in managing this destructive pest. Seven days after treatment, the softer (less toxic) pesticides; Organocide[tm], horticultural mineral oil, and Safer® Soap, did not provide acceptable control with 21%, 47% and 5% mortality, respectively, of the second instar nymphal population on the underside of the leaflets. The best results with foliar treatments, 85% mortality, were with dimethoate (Cygon 2E). In another test, even greater mortality, 95%, of the adult female stage was achieved with a dimethoate (Cygon 2E) root drench (2 oz/gal per plant). The egg-devouring larvae of the imported predator beetle, Cybocephalus binotatus, appear to have become more widespread and a factor in reducing above ground populations of CAS.
